A known diesel particulate filter (DPF) is arranged in an exhaust passage of a diesel engine to capture particulate matters (PM) contained in the exhaust gas. In such DPF, a regeneration process of incinerating the particular matters captured by the DPF using the exhaust gas is carried out to maintain the capturing function of the particulate matters.
For example, in an exhaust gas purifying device of patent document 1, a burner is arranged at a pre-stage of the DPF, and a combustion gas is generated in the combustion chamber of the burner. The temperature of the exhaust gas that will flow into the DPF is raised by supplying the combustion gas to the exhaust gas in the exhaust passage.
A burner of premixing type that supplies the gaseous mixture of fuel and air to the combustion chamber without individually supplying the fuel and the air to the combustion chamber to enhance the ignitability and the combustibility of the gaseous mixture and to reduce the unburned fuel contained in the combustion gas is known for such burner.